Time cycle controller



Dec. 10, 1940.

W. J. BROWN ETAL TIM E' CYCLE CONTROLLER Filed May 23, 1939 ATTORNEY.

Patented Dec. 10, 1940 PATENT osrics 2,224,593 TIME CYCLE CONTROLLERWilliam J. Brown and Paul J. Good, Rochester,

N. Y., assignors to Taylor Instrument Companics, Rochester, N. X, acorporation of New York Application May as, 1939, Serial No. 275,172

3 Claims.

This invention relates to time cycle controllers. In many industrialprocesses it is necessary to control the sequence and duration of aseries of steps or operations involved therein. In order to effect thisresult, it is the practice to utilize a device known as a time cyclecontroller. Since the duration of the various steps or operations varywith different types of products, it is necessary that the controller bereadily changeable by a simple adjustment so that the process operationscan be quickly varied atwill. Such a controller must be reliable inoperation since the failure of the controller to establish thepredetermined sequence and to measure accurately the duration of theseveral operations will result in a defective product. Furthermore, thecontrollershould be of simple construction so that it can be easilyrepaired since it is usually employed in connection with an expensivemachine which is disabled if the controller fails.

The main feature of the invention relates to,

' a time cycle controller of simple and effective construction which isrelatively inexpensive to manufacture and which will be reliable over along period of service.

Another feature of the invention relates to a time cycle controller inwhich the time interval or intervals can be readily changed'withoutdisassembling the controller and without the need of adjusting tools.

These and other features of the invention will appear from the detaileddescription and claims when taken with the drawing in which Fig. 1 is afront elevation of a time cycle controller of the present invention withthe enclosing case thereof omitted. and with certain parts broken awayin order to disclose more clearly the details of construction; and Fig.2 is a plan view of the controller of Fig. 1 with portions thereofbroken away to illustrate more clearly the arrangement of certain parts,the switch shaft and control switches being omitted for the sake ofclarity.

The time cycle controller of the present inven tion includes severaloperation-determining elements such as circuit-controlling switches SIto S5 actuated by a cam follower 5 in cooper-' ation with a rotatabletiming cam G which is driven through a gear train at .a selectivelyvariable rate from a fixed speed motor M.

The motor M, although it may be of the spring type, is preferablyasynchronous electrical motor such as is used in time clocks. This motoris mounted on the front of the frame plate -8 and has its driving shaft9 projecting toward the rear of the controller through the dial bushingill in the frame plate. On this motor shaft there is secured an arm Hwhich has a pawl l2 pivoted on its upper end. This pawl at its righthand end, as viewed in Fig. 1, engages a ratchet wheel 5 l 3. Theratchet wheel is secured to a stub shaft it having its rear endjournaled as at l5 in the rear frame plate Iii, the forward end of thisshaft being recessed so that it can rotate on the free end of the motorshaft 9 as a bearing. The 10 left end of the pawl I2 is provided with anotch ll adapted to be engaged by a hook it on the upper end of a latchl9 pivoted at on 2. lug 2i integral with the arm II. This latch isnormally urged in a clockwise direction by a coil is spring 22 havingone end connected to the upper portion of the latch l9 and having itsother end connected to the lower end of an arm 23 integral with andextending downwardly from the pawl 52. The lower end of the latch i9 isprovided 20 with an angular extension 24 which travels in a path wherebyit periodically engages the pin 25. This pin is fixed on the rearsurface of an adjustable dial disk 26 serving to determine the variablerate at which the gear train T is driven by the fixed speed motor M.This dial, which is rotatably mounted at the rear of the frame plate 8on the dial, bushing H], has its front surface graduated, forobservation through the window 21 in the plate 8. The dial is providedwith a rearwardly projecting peripheral flange 28. This flange isprovided with a series of holes 29 therethrough for engagement with aball-type lock 30 mounted on the frame plate 8 so that the ball of thelock will enter one of the openings of the flange and thus retain thedial in the position to which it has been rotated during axljustment. Itwill be understood that the surface of the flange 28 may be knurled, ifdesired, so that the dial may be manually adjusted. The 4 rearframe'plate l6 has adjustably mounted in an arcuate slot therein aforwardly extending fixed pin 3| projecting in the path of the rounded'top portion 32 of the pawl I2 so that in the course of the rotation ofthe pawl, the pin 3| will depress the left hand end of the pawl, thatis, move it in a counterclockwise direction until the latch l9 engagesthe notch ll. In this way the driving pawl will be disengaged from theratchet wheel l3 during each revolution of the motor shaft and will notbe reengaged therewith until the extension 24 on the latch strikes thepin 25 on the adiustable dial .26, whereupon the latch l9 disen- 5sgages the notch I! in the pawl. This permits the helical spring 22 todraw the pawl into reengagement with the ratchet wheel so that it isagain driven by the motor during the remainder of a given revolution ofthe motor shaft.

On the shaft l4 of the ratchet wheel l3 there is secured a pinion 33which is a part of the gear the pinion 31.

train including the gears 34, 36, 36, 31 and 36. It

should be mentioned that a friction brake is provided to prevent thegear train from coasting when the pawl l2 disengages the ratchet wheel[3. Although this brake can be made in various forms it preferablyconsists of a spring washer B which continuously engages a surface ofthegear 34, as best illustrated in Fig. 2. The gear 33 is secured on therear end of a shaft 39, to the front end of which the timing earn 6 issecured as by a nut 46. This shaft is mounted both for longitudinal androtary movement in a cylindrical bearing 4| secured on the frame plate6. A spiral spring 42 surrounding the forward portion of this bearin itsfront end engaging the rear of the timing earn 6 and has its other endengaging the front of the frame plate 3. By this construction the cammay be forced rearwardly against the action of the spring 42 todisengage the gear 36 from sired part of the cycle. However, when themanual pressure is withdrawn from the cam, the spring 42 will return thegear 36 into mesh with It will be understood that the size of the teethon the gear 36 and pinion 31 troller than can be eflected by theadjusting dial 26, sector plates 43 and 44 are adjustably secured to thecam, to change its contour at will. The sector plate 43, the outline ofwhich is shown partially in full and partially in dotted lines in .Fig.1,-is rotatably mounted on the shaft 39,

being secured to the cam in various positions by any suitable means.However, the present securing arrangement includes an arcuate slot 46concentric with the shaft 39, through which slot there extends anadjusting screw 46 engaging a threaded opening in the sector plate, sothat the plate can be clamped against the rear face of the main cam 6.

In order to indicate at what time in the cycle the high spot of thesector 43 becomes effective,

' there is provided on the sector an index 41 which projects through anarcuate slot 48 in the timing cam 6 which slot, like the slot 46, isconcentric with the shaft 39. The surface of the cam in the path of theindex 41 may be provided with suitable graduations indicating units oftime or other units of measure, to assist the operator in determiningthe adjustment of the sector 43.

A sector 44 of the outline indicated in Fig. l, is also rotatablymounted on the shaft 39 and is clamped to the rear surface of the cam bymeans of the clamping screw 49 passing through the arcuate slot 60 incam 6 into the sector. Similar- 1y, an index 5| secured on the front ofsector 44 projects through the arcuate slot 62, which slot,

' like slot 56, is concentric with the shaft 39. It

The composite periphery of the cam 6 and the sectors 43 and 44 isengaged by the angular portion 63 of the follower arm 6' which ispivoted at 64 on the frame. As herein illustrated, the rear arm 66 ofthe follower operates through a link 66 to rock a switch or controlshaft 61. This shaft which is supported for rocking motion in thebrackets 63 and 69 carried by the frame plate 3, has mounted thereon aseries of electrical switches SI and S6 inclusive, preferably of themercury bottle type. Since these switches have their principal axesarranged at different inclinations with respect to the axis of therocking shaft, they operate at different times as this shaft is rocked.These switches may, for example, control the operations of various typesof processing machines. It will be understood, however, that instead ofusing mercury type switches, the follower may actuate a series of pilotor air relay valves, as disclosed in the patent to Foote No.

At the end of each cycle of the controller, the end portion 63 of thefollower is resting on the low point 66 of the cam, as indicated indotted lines in Fig. 1. When the operator starts the timer in operationby means not shown, the motor M rotates the shaft 9 continuously. Sincethis shaft carries the arm ll together withthe pawl l2 and the latch l9mounted thereon, in a clockwise direction, during a part of eachrevolution of the shaft 9 and the arm II, the pawl 12 is in engagementwith the teeth of the ratchet wheel l3 so that the gear train operatesto drive the cam 6. As the rounded part 32 of the pawl passes under thefixed pin 3|, the pawl is disengaged. from the ratchet wheel and is helddisengaged by the latch l9 which engages the notch I6 on the pawl. Whenthis takes place, the gear train T stops. However, in the course of therotation of the arm II, the pin 25 on the adjustable dial 26 engages theextension 24 on the latch l9 so that this latch is forced to disengagethe notch in the pawl. Thereupon the spring 22 causes the pawl toreengage the ratchet wheel.

Thus, during each revolution of the motor shaft, the ratchet wheel andconsequently the gear train driven thereby, stops for a period ofadjustable duration. It will be understood that by rotating the dial 26,the length of the stopping period in each cycle can be varied at willwithin the limits of adjustment.

As the motor M drives the cam 6, the end portion 53 of the follower arm5 travelsup the inclined portion 6| of the cam and up the inclinedportion 62 of the sector 43. At it does so, the follower 5 rocks theshaft 51 forward thereby completing the operation of certain of themercury switches Si and S6. As the follower drops down to the mainperiphery 63 of the cam, certain of the switches are completely operatedto effect their control in the cycle. Toward the con clusion of thecycle,'the end portion 53 of the follower drops to the portion 64 of theperiphery of the cam and then eventually to its dotted line position inengagement with the low portion 60 to effect operation of certain othersof these until its index 41 is opposite the graduation on uationindicating the desired setting.

From the foregoing it will be seen that there has been provided a timecycle controller in which a substantially fixed speed motor operatesthrough adjustable means to drive a cam at any desired rate, without theneed of change gears or the like.

We claim:

1. A timing mechanism comprising elements to be operated in apredetermined sequence and for predetermined periods, means including arotatable cam and a follower actuated thereby for operating saidelements, means for driving said cam at a predetermined rate, said camincluding a disk having an outline of predetermined contour and havingan arcuate slot therein concentric with the axis of rotation thereof, -asectoran index on said sector projecting through saidsecond slot. 7

-2. In a device of the class described, control mechanism, including acam and follower cooperating therewith for operating said mechanism,means including a ratchet wheel for driving said cam at any one ofseveral selected rates, an arm mounted for rotation about the axisofrotation of said ratchet wheel, a pawl mounted on said arm in a positionto engage said ratchet wheel, means for normally holding said pawl inengagement with said ratchet wheel, a latch on said arm for holding saidpawl out of engagement with,

said ratchet when disengaged therefrom, means mounted in a position todisengage said pawl from said ratchet wheel during each rotation of saidarm, means adjustable in an arcuate path and serving to unlatch saidlatch whereby said mounted for rotation about the axis of rotation ofsaid ratchet wheel, a pawl mounted on said arm in a position to engagesaid ratchet wheel, spring means for normally holding said pawl inengagement with said ratchet wheel, a latch on said arm for holding saidpawl out of engagement with said ratchet when disengaged therefrom, apin mounted in a position to disengage said pawl from said ratchet wheelduring each rotation of saidrarm, a second pin adjustable in an arcuatepath and serving to unlatch said latch whereby said pawl reengages saidratchet wheel.

WILLIAM J. BROWN. PAUL J. GOOD.

